A variable vane arrangement for a turbomachine, as disclosed in our UK patent application GB2339244A, comprises a plurality of circumferentially arranged vanes, a plurality of operating levers and a control ring. Each vane comprises an upstream portion secured to a casing and a movable downstream portion pivotally mounted to the casing of the turbomachine. Each operating lever is pivotally mounted at a first end to the control ring and each operating lever is mounted at second end to a spindle of the movable downstream portion of a respective one of the vanes. Rotation of the control ring causes the levers to adjust the angular position of the movable downstream portions of the vanes.
In this variable vane arrangement the movable downstream portions of the vanes are pivotally mounted about an axis adjacent the upstream ends of the movable downstream portions and downstream of the downstream ends of the fixed upstream portions of the vanes.
Current designs of variable vane arrangements use expensive and difficult to produce drive features between the operating levers and the spindles of the vanes. The drive features may comprise highly toleranced flat surfaces, which require intricate removal tooling and which may damage the lever and spindle on removal. If a clearance is provided to enable easier fitting and removal, there is an increase in the possibility of errors in the angular position of the vanes. During build of the variable vane arrangement it is difficult to both load the variable vane and maintain it in position while attempting to fit the highly accurate drive features.